Quick-clamping box type jig



Patented Feb. 13, 1934 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to improvements in jigs and more particularly to quick-clamping box type igs.

It is an object of this invention to provide a means for quickly clamping material to be drilled and hold it firmly during the drilling, providing a locking means that may be applied to the commercial die sets and produce a reversible jig at the same time.

With these and other objects in View, reference is made to the accompanying sheet of drawing which illustrates preferred forms of this invention with the understanding that minor detail changes may be made without departing from the scope thereof.

In the drawing, Figure l is a view in side elevation illustrating one form of this invention, showing the parts in lock position in full line and in extended and unlocked position in dotted lines.

Figure 2 is a top plane view of Figure 1.

Figure 3 is a view similar to Figure 1 of the modified form.

Figure 4 is a view similar to Figure 3 illustrating the relation of the parts in extended and unlocked position.

In the embodiment of this invention illustrated, the base plate 1 mounts the bushing plate 2 to travel over the guide posts 3 carried on the base plate in the accustomed manner of commercial die sets. The bushing plate is operated to reciprocate over the guide posts 3 by means of the handle 4, preferably constructed of spring steel, and which is slit at one end to form bifurcations 5 and 6. The bifurcation 5 mounts upon the pivot pin 7 at the extremity of said bifurcation one end of a curved link 8 which is pivotally mounted by the pivot 9 to the center of the bushing plate 2. The other bifurcation 6 is pivotally mounted upon the pivotlO at the extremity of the bifurcation upon the curved arm 11 rigidly secured by bolts or screws 12 to the base plate 1 in such a manner that when the handle 4 is in the position shown in full lines, the pivots 9 and 10 will lie in the same plane which passes through the vertical centers of the base and bushing plate and the pivot 7 will assume a position off center and to the right of said plane. Upon rotation of the handle 4 to the position indicated in the dotted lines on Figure 1, it is readily seen that the bushing plate will be quickly and positively moved away from the base plate. The work is placed upon the base plate when the parts are separated and upon returning the handle to the position shown in full lines, the work will be engaged between the base and bushing plate, the handle being of spring steel, the bifurcations 5 and 6, as the handle is rotated to carry the pivot 7 beyond the centers of pivots 9 and 10, will through link 8 exert tension upon the work engaged and the off-center position of the lower pivot will positively lock the jig and hold the work between the base and bushing plate.

In the form illustrated in Figures 3 and 4, the handle is of the same construction as above described and carries the link 8 in the same manner which is mounted at the other end in the same manner upon the bushing plate. In this form, however, the bifurcation 5 of the handle mounts upon the pivot 10 one end of a link 13, the other end of which is mounted upon the pivot 14 upon the base plate 1. at one end to the respective bushing plate and base in a plane which passes through the vertical centers of these parts. The link 13 is of such shape that when the handle 4 is in position shown in Figure 3, the pivot 10 lies in the same plane with pivots 9 and 14 and the link 8 will have carried the pivot 7 to the right of said plane, whereby its off-center position will lock the base and bushing plate in the same manner as shown in Figure 1.

Bushings 15 are shown upon the jig plate for the drills to pass through and bushings 16 are also shown upon the under side of the base plate 1 whereby the jig may be reversed and the work may be drilled from either side of the jig.

What I claim is:

1. A quick-clamping box jig including a base plate, a plurality of guide posts thereon, a bushing plate mounted to reciprocate thereover, and means to reciprocate the bushing plate including an arm carried on the base mounting a pivot, an arm pivoted above said first arm on the bushing plate, both pivots lying in the vertical center plane passing through the base and bushing plates, said second arm extending below the pivot on the first arm and mounting a pivot on its free end, an operating handle having bifurcated resilient extensions with the extremity of the lower extension mounted on the pivot carried by the upper arm and the extremity of the upper extension mounted on the pivot carried by the lower arm, said handle adapted upon rotation in one direction to move the said base and bushing plates apart and upon rotation in the opposite direction to move said plates toward each other, and in the lowermost position to carry the handle pivot of the upper arm beyond the said vertical center plane of the said plates and hold said plates in the The links 8 and 13 are pivoted one direction moves the said plates apart and rotation in the opposite direction draws the said plates together, and in the lowermost position carries one of the handle pivots off center to the other three pivots to hold said plates against movement and wherein the handle is of spring material and slit longitudinally at the pivoted end between the pivots.

FRED W. KUPPERSMI'IH. 

